Malpractice claim payouts for diagnostic errors amounted to $38.8 billion between 1986 and 2010, according to a study published online April 22 in BMJ Quality and Safety.

That makes diagnostic errors—as opposed to surgical mistakes or medication overdoses—the most common, costly and harmful of all malpractice allegation groups, according to David E. Newman-Toker, MD, PhD, of Johns Hopkins University School of Medicine in Baltimore, and colleagues.

“Healthcare stakeholders should consider diagnostic safety a critical health policy issue,” wrote the authors.

Findings were based on an analysis of 25 years of closed, paid malpractice claims from the National Practitioner Data Bank. A total of 350,706 paid claims were included in the study. Diagnostic error was defined as a diagnosis that was missed, wrong or delayed based on subsequent testing.

Among 11 primary malpractice allegation categories, diagnostic errors, at over 100,000 paid claims, accounted for the highest proportion with 28.6 percent of all claims. They also accounted for the highest proportion of total payments at 35.2 percent, according to Newman-Toker and colleagues.  

The results of diagnostic errors in the claims data were often quite serious, with nearly 41 percent resulting in death, a rate twice that of other allegation groups, according to the authors. Permanent morbidity was the result in 44.2 percent of claims, with the highest per-claim payments made for neurologic outcomes.  

“We found roughly equal numbers of lethal and non-lethal errors in our analysis, suggesting that the public health impact of diagnostic errors could be substantially greater than previously estimated based on autopsy data that consider only lethal errors,” wrote Newman-Toker and colleagues.

More than two-thirds of diagnostic error claims were outpatient, but inpatient diagnostic errors were more likely to be fatal, according to the authors.

The inflation-adjusted $38.8 billion total for diagnosis-related claims between 1986 and 2010 translated to $1.6 billion per year and $386,849 mean payout per claim.

Diagnostic errors receive relatively limited public and scientific attention despite their impact, noted the authors. They acknowledged the complexity of the situation in trying to balance costs and quality of care, limiting false positives while also being mindful of “defensive medicine.”

The authors suggested error-reduction initiatives focused on misdiagnosis and said strategies to reduce costs by streamlining diagnostic testing protocols should consider both direct and indirect costs of diagnostic errors. They also called for further research to define when harms from diagnostic errors are greatest.